Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
Do you need help with all of these?
Answer:
x = 59°
y = 67°
Step-by-step explanation:
x = y - 8
x + y + 54 = 180
(y - 8) + y = 180 - 54
2y - 8 = 126
2y = 134
y = 67°
x = 59°
Step-by-step explanation:
Answer:
0.5 ft^2
Step-by-step explanation:
The area in square inches is (6 in )(12 in) = 72 in^2.
Recall that 1 ft^2 = 144 in^2.
Then
72 in^2 1 ft^2
--------------- * --------------- = 0.5 ft^2
1 144 in^2
